Opposite
Noun, する verb, な adjective, and の adjective
はんたい
その考えには反対です。
I’m opposed to the idea.
不自由の男神は、アッパーわんをはさんで、自由の女神の反対がわに立っています。
The Statue of Restriction is standing on the opposite side of the Statue of Liberty in middle of the Upper Bay.
チェンジビルに引っ越してからというもの、あいつは昔のあいつとは正反対の人間になっちまったんだ。
He’s the complete opposite of what he used to be like ever since he moved to Changeville.
The anti versus... You'd think this would be a double negative, but it's like a lot of other words where you have two similar words combined... it just means the same thing as those two words. In this case, the anti-versus of something would be the opposite. Alternatively, it can be the opposition. You choose.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.